Question

the speed of a car increases from 10m/s to 20m/s with an acceleration of 3.0 m/s^2. Find the distance covered during the acceleration.

Answer 1

v^=u^2+2as
20x20=10x10+2x3xs s=distance covered
400=100+6s
s=50meters

Answer 2

by 3rd eqn of motion

Answer 3

I got it now. thanks a lot :)

Answer 4

This is again conservation of energy.

Work = (Force)x(distance)
= Fs
= mas

But Work = Change in KE
= (1/2)mv^2 - (1/2)mu^2
= (m/2)(v^2 - u^2)

Hence

mas = (m/2)(v^2 - u^2)

or

v^2 - u^2 = 2as